Several mud-caked headstones line the banks of a small stream at Arlington National Cemetery, the country's most venerated burial ground. Farther upstream in a wooded area, a few others lie submerged with the rocks that line the stream bed.

On Wednesday, after The Washington Post alerted the cemetery to their presence, officials there said they were shocked to find the gravestones lying in the muck near a maintenance yard. Already under fire in recent days for more than 200 unmarked or misidentified graves and a chaotic and dysfunctional management system, cemetery officials vowed to investigate the headstones along the stream and take "immediate corrective action," said Kaitlin Horst, a cemetery spokeswoman.

Officials said they do not know how the stones got there, whom they belong to, or how old they are. Horst could say only that "they appear to be decades old."

Were they used as riprap to prevent stream erosion? Were they engraved incorrectly and then discarded? Or were they intended for a landfill -- where thousands of weathered or damaged burial markers routinely were sent years ago -- and ended up in the mud instead?

One of the headstones offers some clues. It has a cross in a circle at the top, a design that Horst said was discontinued in the late 1980s. And there is writing. It is worn and faded but seems to identify the person as a Navy captain, whose name is something like J. Warren McLaughlin.

Or is it L. Warren McLaughel?

Cemetery officials said they do not know, but they vowed to research their records.

Efforts Wednesday by Post researchers to learn more about the captain's identity and military record were unsuccessful.

"At this point, we won't be able to tell until we can get in there to reclaim them," Horst said.

The stream runs under Ord & Weitzel Drive in the northwest corner of the cemetery, across from Section 28. Some of the headstones, stacked in pairs along the stream bed, are visible from the roadway. Others are farther upstream, under a dense canopy of trees.

The discovery follows an investigation of the cemetery by the Army's inspector general, which found 117 graves that are marked on maps as occupied on but have no headstones. The inquiry found 94 more marked on maps as unoccupied even though they have gravestones. In addition, the investigation found that at least four burial urns were unearthed and dumped in an area where excess dirt is kept.

As a result of the scandal, the Army reprimanded Superintendent John C. Metzler Jr., who is retiring July 2, and his deputy, Thurman Higginbotham, who was placed on administrative leave pending a disciplinary review.

Army Secretary John McHugh appointed a new team to oversee cemetery operations and continue the investigation, which officials said could find even more unmarked grave sites.

Joe Davis, a spokesman for the Veterans of Foreign Wars, said he was "stunned" to learned about the discarded headstones.

"Arlington National Cemetery is truly hallowed ground to this entire nation," he said. "It is an honor to be buried at Arlington. It is an honor to work at Arlington. And over the past week, we're finding out that people are just not doing their jobs."

Horst said that the cemetery's new superintendent, Patrick K. Hallinan, a longtime cemetery official with the Department of Veterans Affairs, checked out the streamside headstones and ordered their removal.

"They will reclaim the stones and dispose of them properly in accordance with our current headstone-disposal policy," Horst said.

Headstones are replaced if they are damaged or if the writing on them becomes illegible, she said. At one time, gravestones were discarded in landfills. The cemetery ended that practice because Washington area residents were plucking the stones and using them for patios, driveways and other home improvement projects. Under the current disposal policy, headstones are to be ground up so the names cannot be recognized and then recycled.